Brother MFC-8640D is a monochrome (black and white) multi-function laser printer. It functions as an all in one laser printer, scanner, digital copier, fax and PC fax. This model has a 250 sheet total media capacity and 150 sheet output capacity, the maximum duty cycle is 20,000 printed pages. The print resolution is 2400 x 600 dpi and the scanner resolution is 600 x 2400 dpi. The Brother MFC-8640D print speed is 21 pages per minute and the copier speed is 21 copies per minute. The media size for this model are letter A size, executive, legal, A4, A5, A6 and B5. The media type is plain paper. It also features automatic duplexing, 16 MB memory, USB and parallel connectivity. The Brother MFC-8640D uses two toner cartridges and one drum unit, the toner cartridges consist of a standard yield and a high yield toner. The standard yield can print up to 3,000 pages at 5% coverage, while the high yield can print up to 6,000 pages at 5% coverage. The toner cartridge model numbers are TN540 (TN-540) which is the standard yield and TN580 (TN-580) which is the high yield toner. The drum unit model number is DR510 (DR-510), which has a duty cycle of 20,000 pages at 5% coverage.